/*
 * Copyright (C) 2008, 2010 Apple Inc. All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1.  Redistributions of source code must retain the above copyright
 *     notice, this list of conditions and the following disclaimer.
 * 2.  Redistributions in binary form must reproduce the above copyright
 *     notice, this list of conditions and the following disclaimer in the
 *     documentation and/or other materials provided with the distribution.
 * 3.  Neither the name of Apple Inc. ("Apple") nor the names of its
 *     contributors may be used to endorse or promote products derived
 *     from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY APPLE AND ITS CONTRIBUTORS "AS IS" AND ANY
 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED. IN NO EVENT SHALL APPLE OR ITS CONTRIBUTORS BE LIABLE FOR ANY
 * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

#ifndef SKY_ENGINE_WTF_TEXT_STRINGBUFFER_H_
#define SKY_ENGINE_WTF_TEXT_STRINGBUFFER_H_

#include "flutter/sky/engine/wtf/Assertions.h"
#include "flutter/sky/engine/wtf/text/StringImpl.h"
#include "flutter/sky/engine/wtf/unicode/Unicode.h"

namespace WTF {

template <typename CharType>
class StringBuffer {
  WTF_MAKE_NONCOPYABLE(StringBuffer);

 public:
  StringBuffer() {}

  explicit StringBuffer(unsigned length) {
    CharType* characters;
    m_data = StringImpl::createUninitialized(length, characters);
  }

  ~StringBuffer() {}

  void shrink(unsigned newLength);
  void resize(unsigned newLength) {
    if (!m_data) {
      CharType* characters;
      m_data = StringImpl::createUninitialized(newLength, characters);
      return;
    }
    if (newLength > m_data->length()) {
      m_data = StringImpl::reallocate(m_data.release(), newLength);
      return;
    }
    shrink(newLength);
  }

  unsigned length() const { return m_data ? m_data->length() : 0; }
  CharType* characters() {
    return length() ? const_cast<CharType*>(m_data->getCharacters<CharType>())
                    : 0;
  }

  CharType& operator[](unsigned i) {
    ASSERT_WITH_SECURITY_IMPLICATION(i < length());
    return characters()[i];
  }

  PassRefPtr<StringImpl> release() { return m_data.release(); }

 private:
  RefPtr<StringImpl> m_data;
};

template <typename CharType>
void StringBuffer<CharType>::shrink(unsigned newLength) {
  ASSERT(m_data);
  if (m_data->length() == newLength)
    return;
  m_data->truncateAssumingIsolated(newLength);
}

}  // namespace WTF

using WTF::StringBuffer;

#endif  // SKY_ENGINE_WTF_TEXT_STRINGBUFFER_H_
